1. Field of the Invention
The present invention relates to an ordnance control and initiation systems and methods useful for managing and controlling the activation of ordnance, for example, such as those used for stage separation in flight vehicles. The system and method, for example, may relate not only to ordnance safing, arming and initiation, but monitoring and telemetry acquisition as well.
2. Description of the Related Art
There are numerous applications in which it is necessary or desirable to control and/or initiate ordnance with high precision and reliability. One such application, although merely illustrative and not by way of limitation, involves the ordnance associated with rockets, missiles, and similar powered flight vehicles (hereinafter xe2x80x9cflight vehiclesxe2x80x9d). It is not uncommon for such vehicles to include a plurality of ordnance devices for performing interrelated or distinct tasks. By way of example, a flight vehicle may contain multiple stages, with each stage having its own distinct ordnance in the form of a gas generant or propellant. In some instances, a flight vehicle stage may have multiple gas generants or propellants, such as found in the case of rocket motor stages having main and divert motors. Each of these gas generants and propellants typically has its own distinct initiator for activating (directly or by an ignition train) the gas generant and propellant.
Another illustrative use of ordnance devices in multi-stage flight vehicles involves stage separation. As a lower stage is depleted of gas generant or propellant, the depleted lower stage must be separated from the remaining upper stage or stages before the next stage can be fired. This stage separation is typically performed with ordnance devices, each of which must be activated with precise timing for successful stage separation.
Another example of the use of ordnance devices on a flight vehicle, especially a multi-stage flight vehicle, can be found at the uppermost or xe2x80x9ckillxe2x80x9d stage of a missile. The kill stage often has a first ordnance device in the form of a gas generant or propellant for propelling the kill stage, and a second ordnance device in the form of an explosive for imparting maximum damage to its intended target.
Further examples of ordnance device applications on flight vehicles include the use of solid or liquid fuel ordnances on launch vehicles for propelling devices, such as satellites, into space. As yet another example, a flight vehicle may contain destruct (explosive) ordnances for destroying the vehicle or its cargo or payload in the event of a malfunction or error in launch trajectory or flight control.
The ordnance devices of flight vehicles require an ignition event for activation of the ordnance device or initiation of an ignition train that results in activation of the ordnance device. Typically, each ordnance device of a flight vehicle is associated with its own initiator. The initiator typically includes a squib having a bridge wire and pyrotechnic material. A pyrotechnic reaction is initiated by sending electrical energy to the squib, which converts the electrical energy to thermal energy until the bridge wire reaches a sufficiently high temperature to ignite the pyrotechnic material of the squib. The pyrotechnic material then either ignites the propellant/gas generant directly or ignites an ignition train that leads to the ignition of the propellant/gas generant.
Known electrical ignition systems have several drawbacks. Perhaps the most significant one is the possibility of unintentional activation of the ordnance, e.g., caused by unwanted and unplanned electromagnetic energy or fields, such as electromagnetic interference, lightning, electrostatic discharge, etc. This drawback in some cases and to some extent may be mitigated by heavily shielding the electrical system to shield it against such external electrical phenomena. However, shielding of the electrical system adds production costs and makes testing and installation difficult. It also adds to system mass.
Another drawback of some known electrical ordnance systems is their requirement for sometimes lengthy and relatively heavy conductor cabling, such as twisted pair cabling, and the associated shielding and harnesses. Such systems can be disadvantageous, for example, based on their relatively high mass penalties, relatively substantial installation requirements, and high rework difficulty. Electrical conductors also can be subject to relatively substantial power losses when they run for significant distances. Large, heavy pyrotechnic controller black boxes often are required to interface commands from the command computer to the ordnance devices.
It is often desirable in ordnance applications to have the flexibility to scale the system, for example, by adding additional ordnance devices. When this is done with many known systems, it typically requires additional control circuits and cabling. As a consequence, for example, it is often not feasible or unduly difficult or penalizing to integrate a telemetry system with the ordnance system. In such cases it is often necessary for the transmission lines and controllers of the telemetry and ordnance systems to remain discrete from each other.
Another approach, often used as an alternative to the electrical activation system, involves the use of electro-optics. In such systems, for example, electrical control and/or initiation signals are converted into optical signals and transmitted via optical signal conduits, such as a fiber optic cable. The optical energy is used to transmit power and optionally commands through an optical fiber system to the squib. Such systems, however, also may have drawbacks. For one, the power transmission capacity of optical conduits typically is relatively limited. Moreover, optical transmission can be subject to substantial energy loss over long distances, particular at relatively high power levels. For this reason, optical initiation systems are often are not suitable for large vehicles having lengthy optical conduits. optical transmission. Another drawback in some electro-optic systems involves the potentially substantial amount of cabling or optical conduit runs to couple the controller to the ordnance devices.
Accordingly, an object of the present invention is an ordnance control and initiation system and method that are reliable relative to known systems and methods, and thus which limit or preclude inadvertent ignition of the ordnance.
It is another object of the invention to provide an ordnance control and initiation system and method that can have lower overall mass relative to known systems and methods having like overall functional capability.
It is also an object of the invention to provide an ordnance control and initiation system and method that offer the flexibility to be scalable.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims.
To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, an ordnance control and initiation system is provided. It comprises a plurality of ordnance devices comprising a plurality of sets of the ordnance devices. Each set of the ordnance devices comprises at least one of the ordnance devices and an ordnance device interface. The system also comprises a controller for issuing state commands, a master ignition control module operatively coupled to the controller to receive the state commands and re-transmit the state commands, and a plurality of slave ignition control modules. Each of the slave ignition control modules is associated with one of the sets of the ordnance devices and is operatively coupled to the master ignition control module and optically coupled to the ordnance device interface of the one of the ordnance device sets of that slave ignition control module. Each of the slave ignition control modules receives the state commands and retransmits the state commands to the ordnance devices of the one of the ordnance device sets of that slave ignition control module.
Preferably, the ordnance device interface of one of the ordnance device sets comprises an optical-to-electrical converter. Each of the ordnance devices of the one of the ordnance device sets preferably comprises a capacitor device operatively coupled to the optical-to-electrical converter so that the capacitor device is charged when light from the slave ignition control module corresponding to that ordnance device set impinges upon the optical to electrical converter. In the presently preferred embodiments, each of the ordnance devices comprises an initiator operatively coupled to the capacitor to receive electrical energy from the capacitor when the capacitor is discharged. Preferably, one of the ordnance device sets comprises a plurality of the ordnance devices, each of the ordnance devices of the one ordnance device set comprises an initiator, and the ordnance device interface of the one of the ordnance device sets comprises a plurality of optical-to-electrical converters corresponding in number to the number of ordnance devices of the one ordnance device set, wherein each of the ordnance devices of the one of the ordnance device sets has an associated one of the optical-to-electrical converters. Also preferably, each of the ordnance devices of the one of the ordnance device sets comprises a capacitor device operatively coupled to the associated optical-to-electrical converter so that the capacitor device is charged when light from the slave ignition control module corresponding to that ordnance device impinges upon the associated optical-to-electrical converter.
The ordnance devices may comprise, for example, a semiconductor bridge initiator, e.g., comprising titanium subhydride potassium perchlorate, a thin film bridge initiator, or the like.
The state commands may comprise a safe command, an arm command, and a fire command. Optionally but preferably in some application, state commands may comprise a power signal, in which the signal of whatever information content may be used as a source of energy or power also to cause or aid in the initiation of the ordnance device. The state commands comprise an ordnance device address for addressing individual ones of the ordnance device sets, individual ones of the ordnance devices within one of the ordnance device sets, and/or individual ones of the ordnance devices.
The master ignition module preferably is optically coupled to the slave ignition control modules, but may be coupled, for example, electrically.
The system optionally but preferably further includes a monitoring device optically coupled to one of the slave ignition control modules for generating an upstream signal. In this instance, the one of the slave control modules comprises a transmitting device for re-transmitting the upstream signal to the master ignition control module and the master control module comprises a transmitting device for re-transmitting the upstream signal to the controller.
In accordance with another aspect of the invention, an ordnance control and initiation system is provided which comprises a plurality of ordnance devices comprising a first and a second plurality of sets of the ordnance devices. Each set of the ordnance devices comprises at least one of the ordnance devices and an ordnance device interface. The system also comprises a controller for issuing state commands, first and second master ignition control modules operatively coupled to the controller to receive the state commands and re-transmit the state commands, a first and a second plurality of slave ignition control modules, wherein each of the slave ignition control modules of the first plurality of slave ignition control modules is associated with one of the first plurality of sets of the ordnance devices and each of the slave ignition control modules of the second plurality of slave ignition control modules is associated with one of the second plurality of sets of the ordnance devices. Each of the slave ignition control modules is operatively coupled to the master ignition control module and optically coupled to the ordnance device interface of the one of the ordnance device sets of that slave ignition control module, each of the slave ignition control modules receives the state commands and re-transmits the state commands to the ordnance devices of the one of the ordnance device sets of that slave ignition control module.
This aspect of the invention makes clear that the system may be used, for example, to provide multiple channels or paths so that the system has backup and redundancy. Illustrative examples of such redundant systems are provided below in the preferred embodiments.
In accordance with another aspect of the invention, an ordnance control and initiation system is provided for controlling and initiating a plurality of ordnance devices comprising a plurality of sets of the ordnance devices, wherein each set of the ordnance devices comprises at least one of the ordnance devices. The system comprises a plurality of ordnance device interfaces corresponding in number to the number of ordnance device sets, wherein each of the ordnance device interfaces has a corresponding one of the ordnance device sets. The system also comprises a controller for issuing state commands, a master ignition control module operatively coupled to the controller to receive the state commands and re-transmit the state commands, and a plurality of slave ignition control modules. Each of the slave ignition control modules is associated with one of the sets of the ordnance devices and is operatively coupled to the master ignition control module and optically coupled to the ordnance device interface of the one of the ordnance device sets of that slave ignition control module. Each of the slave ignition control modules receives the state commands and re-transmits the state commands to the ordnance devices of the one of the ordnance device sets of that slave ignition control module.
Preferably, the ordnance device interface corresponding to one of the ordnance device sets comprises an optical-to-electrical converter. It is also preferred that each of the ordnance device interfaces comprises a capacitor device operatively coupled to the optical-to-electrical converter so that the capacitor device is charged when light from the slave ignition control module corresponding to that ordnance device set impinges upon the optical to electrical converter. Each of the ordnance devices also preferably comprises an initiator and the capacitor includes coupling means for coupling the capacitor to the initiator so that the capacitor discharges into the initiator. Preferably, for example, one of the ordnance device sets comprises a plurality of the ordnance devices, each of the ordnance devices of the one ordnance device set comprises an initiator, and the ordnance device interface corresponding to the one of the ordnance device sets comprises a plurality of optical-to-electrical converters corresponding in number to the number of ordnance devices of the one ordnance device set, wherein each of the optical-to-electrical converters is associated with one of the ordnance devices of the one of the ordnance device sets. In accordance with another preferred aspect, each of the ordnance device interfaces comprises a capacitor device operatively coupled to the associated optical-to-electrical converter so that the capacitor device is charged when light from the slave ignition control module corresponding to that ordnance device impinges upon the associated optical-to-electrical converter. Other preferred aspects of this system are as described above. In accordance with another aspect of this invention, an ordnance control and initiation system is provided for controlling and initiating a plurality of ordnance devices comprising a first and a second plurality of sets of the ordnance devices. Each set of the ordnance devices comprises at least one of the ordnance devices. The system comprises a plurality of ordnance device interfaces corresponding in number to the number of ordnance device sets, wherein each of the ordnance device interfaces has a corresponding one of the ordnance device sets. The system also comprises a controller for issuing state commands, first and second master ignition control modules operatively coupled to the controller to receive the state commands and re-transmit the state commands, and a first and a second plurality of slave ignition control modules. Each of the slave ignition control modules of the first plurality of slave ignition control modules is associated with one of the first plurality of sets of the ordnance devices and each of the slave ignition control modules of the second plurality of slave ignition control modules is associated with one of the second plurality of sets of the ordnance devices. Each of the slave ignition control modules is operatively coupled to the master ignition control module and optically coupled to the ordnance device interface of the one of the ordnance device sets of that slave ignition control module. Each of the slave ignition control modules receives the state commands and re-transmits the state commands to the ordnance devices of the one of the ordnance device sets of that slave ignition control module.
In accordance with yet another aspect of the invention, a method for controlling and selectively initiating ordnance devices. The method comprises communicating state commands from a controller to a master ignition control module operatively coupled to the controller, communicating the state commands from the master ignition control module to a plurality of slave ignition control modules operatively coupled to the master ignition control module, wherein each of the slave ignition control modules is associated with one of a plurality of sets of ordnance devices and is optically coupled to an ordnance device interface of the one of the ordnance device sets of that slave ignition control module, and communicating the state commands from each of the slave ignition control modules to the ordnance devices of the one of the ordnance device sets of that slave ignition control module. Preferably, the communication from the slave ignition control modules to the ordnance devices comprises performing an optical-to-electrical conversion of the state commands. It is also preferable that the optical-to-electrical conversion comprises charging a capacitor device and selectively discharging the capacitor device into an initiator for each of the ordnance devices. The state commands may comprise a safe command, an arm command, and a fire command. The state commands also may comprise a power signal, as described above. The state commands also may comprise an ordnance device address for addressing individual ones of the ordnance device sets, an ordnance device address for addressing individual ones of the ordnance devices within one of the ordnance device sets, and/or an ordnance device address for addressing individual ones of the ordnance devices.
Communication of the state from of the state commands from the master ignition module to the slave ignition control modules optionally but preferably is optical, but also may be electrical, for example. The method also optionally but preferably comprises optically communicating an upstream signal from a monitoring device optically coupled to one of the slave ignition control modules to the one of the slave control modules, communicating the upstream signal from the one of the slave ignition control modules to the master ignition control module, and communicating the upstream signal from the master ignition control signal to a controller.